The Algerian government said Gaddafi's wife, daughter, two of his sons and their children had crossed the border.

It did not say whether Gaddafi himself was with the family.

It said the UN secretary-general and Security Council and the head of Libyan rebel National Transition Council were informed.

The report came as battles raged on two sides of Sirte, the southern city that is the headquarters of Gaddafi's tribe and his regime's last major bastion. The rebels were consolidating control of Tripoli, the capital.

Despite effectively ending his rule, the rebels have yet to find Gaddafi or his family members - something that has cast a pall of lingering uncertainty over the opposition's victory.

The Egyptian news agency MENA, quoting unidentified rebel fighters, had reported from Tripoli over the weekend that six armoured Mercedes sedans, possibly carrying Gaddafi's sons or other top regime figures, had crossed the border at the south-western Libyan town of Ghadamis into Algeria.

Algeria's Foreign Ministry had denied that report.

Ahmed Jibril, an aide to rebel National Transitional Council head Mustafa Abdul-Jalil, said if the report of Gaddafi relatives in Algeria is true, "we will demand that Algerian authorities hand them over to Libya to be tried before Libyan courts".

The Foreign Ministry said the family members who crossed the land border were Gaddafi's wife Safia, his sons Hannibal and Mohammed, and his daughter Aisha.